By Vanessa Allen, Daily Mail

If you’re middle-aged and miserable, don’t despair: Give it a decade or two and you’ll be feeling like a carefree young person again.

Researchers have revealed that life satisfaction peaks at 23 and 69. People in their early 20s overestimate their future life satisfaction by an average of around 10 percent, before the disappointments of life kick in.

They face decades of declining expectation before hitting their lowest point in their mid-fifties, when regrets over unrealized dreams are at their greatest.

Satisfaction levels finally start to rise again after 55 and peak once more at 69, according to a study by the Centre for Economic Performance at the London School of Economics.

Those aged 68 underestimate their future happiness by 4.5 percent, meaning they no longer face disappointment, the researchers found.

Previous studies have found that human contentment follows a U-shaped pattern, with those in their early 20s and the retired ranking highest.

The pattern has been observed in more than 50 nations and across class and financial divides.

And a study by the National Academy of Sciences in the U.S. found evidence that even great apes can suffer a mid-life crisis.

The CEP paper, published last week, is the first to examine how our expectations compare to reality at different life stages.

Researcher Hannes Schwandt, 30, analyzed happiness levels for 23,161 Germans aged 17 to 85.

Schwandt, who is based at Princeton University, but is a visiting researcher at the London center, said: “One theory is that the U-shape is driven by unmet aspirations which are painfully felt in midlife but beneficially abandoned later in life.

“People in their 50s could learn from the elderly, who generally feel less regret. They should try not to be frustrated by their unmet expectations because they are probably not feeling much worse than their peers.”